1. Field of the Invention
The present invention relates to a cradle for use with a radiation conversion device for performing a charging process for a radiation conversion device, which is arranged in the vicinity of an image capturing apparatus for capturing a radiation image of a subject, the radiation conversion device detecting radiation that has passed through the subject and converting the radiation into image information.
2. Description of the Related Art
In the medical field, a radiation image capturing apparatus, in which radiation is applied to a subject, and radiation that has passed through the subject is directed to a radiation conversion device for capturing a radiation image of the subject, has been widely used.
In this case, a radiation conversion device (electronic cassette) has been developed in which applied radiation is converted directly into electric signals, or after the radiation has been converted into visible light by a scintillator, a solid state detecting element made up from amorphous silicon or the like is used to convert the visible light into electric signals to enable reading thereof. In such a radiation conversion device, pixels made up from a plurality of solid state detecting elements are arrayed in a matrix form, wherein by converting the radiation into image information for each pixel, a two dimensional radiation image can be obtained.
Incidentally, the conversion characteristics of each of the pixels are not all the same, and normally the conversion characteristics differ individually. Further, upon being irradiated with radiation, not only do the conversion characteristics tend to change over time, but in addition, defects may occur in which image information cannot be obtained from individual pixels.
Consequently, a technique has been proposed in which the conversion characteristics of each of the pixels are detected in order to generate correction information, such that the image information obtained when an image is captured can be corrected utilizing the correction information. (See, Japanese Laid-Open Patent Publication No. 2000-132662).
On the other hand, an internal battery may be loaded into the radiation conversion device, so as to form a portable type of device, which can be carried around. In this case, when the capacity of the internal battery is large, since the weight of the radiation conversion device also increases, inconveniences in handling of the radiation conversion device tend to occur. As a result, the storage capacity of the battery is restricted to enable a reduction in weight, whereas in the room where an image is to be captured, or in the vicinity thereof, a charging cradle is arranged, for carrying out charging of the battery at appropriate times. (See, Japanese Laid-Open Patent Publication No. 2006-208306.)
Notwithstanding, because the charging cradle disclosed in Japanese Laid-Open Patent Publication No. 2006-208306 does not have a function for generating correction information for the radiation conversion device, depending on the situation, it is thought that the charging process could be performed needlessly, with respect to a radiation conversion device that is not in a suitable condition.